Can You Use The Apple Watch With An iPod?

I may or may not be be getting the new Apple Watch. Before I think about it I want to know if I can use it with an iPod Touch 5th generation instead of an iPhone.

Is the apple Watch locked to the iPhone 6 only or can I use it with an iPod Touch. If I can use it with a iPod what features will I loose or what will the ones be available.